Fixes #3336.

I know, this is REALLY nasty but that was the only way I've found to
make it work properly.

Fix PSR2 rules : "As per PSR2, the static declaration should come after the visibility declaration."

According to the comment

// deleting duplicated foreign keys present on both on the orphanedForeignKey
// and the removedForeignKeys from changedTables

A check must be had on the $removedForeignKey so it does point on the removed table. Currently it does unset all keys removal even the one pointing on other table.

Updating a schema should introduce also schema creation statements in the generated SQL

- Fixed docblocks
- Removed return statements on void methods
- Cleaned up unused private / local variables
- Fixed license issues
- Removed SVN leftovers
- Fixed doctrine-project.org links
- Added line breaks before return statements